A theoriser is someone who formulates theories, which are ideas or explanations that are based on observations and logical reasoning. They are often used to explain phenomena in the natural world or to develop new technologies. Theorisers use their knowledge and experience to come up with hypotheses and then test them to see if they are correct. They also use their skills to analyze data and draw conclusions from it. Theorisers are important in many fields, such as science, engineering, and economics.